Waking up four years after the end of Halo 3, the Master Chief and his pint-sized AI companion, Cortana immediately get down to business escaping exploding space ships and mowing down alien invaders, the Covenant.

New developer 343 Industries has made changes: the visuals are brighter and crisper, and vehicle handling spritelier. This is Halo with a spring in its step (and impressive co-op mode Spartan Ops), while new enemies the Prometheans come with their own firearms, giving this outing the greatest variety of the series so far.